The invention relates to the field of hydrocarbon well completion fluids, and more particularly to a surfactant package which reduces or eliminates formation damage during the use of the completion fluid.
Hydrocarbon wells for liquid and gas hydrocarbons from subterranean reservoirs involve a well drilled from the surface into communication with the reservoir. At the point of communication between the well and the reservoir, the condition of the reservoir around the well is a very sensitive and important region.
Early in the life of a well, drilling fluids and other fluids are used to lubricate the drill bit, carry cuttings from the formation to the surface and balance pressure within the reservoir. These drilling fluids are completely different in composition from fluids used later in the preparation of the well which are known as workover or completion fluids, and which will be collectively referred to herein as completion fluids.
Completion fluids are typically much lighter than drilling fluids used earlier in the life of the well. Further, completion fluids are typically used, among other things, for removing traces of drilling fluids and the like from the well to the greatest extent possible to prepare the well for use in producing hydrocarbons. A concern exists with respect to completion fluids, which can invade the surrounding reservoir from the well, for example due to over pressure of the fluid in the well column as compared to the formation. These fluids invading the reservoir can change the characteristics of the reservoir and have an adverse impact on the ability of hydrocarbons in fluid and gaseous form to flow through the reservoir and to the well for production to the surface.
It is a focus of this invention to provide a completion fluid which addresses this issue.